Your Care Explained > Medications : Warfarin

Warfarin is a widely prescribed anticoagulant used to treat or prevent clots from developing in the veins, arteries, lungs and heart and on medical implants.

Decades of use have proven its effectiveness, but it must be used with care to avoid side effects. If you even think you’re pregnant, tell your doctor. Warfarin can harm a developing fetus, especially in the first trimester.

How Warfarin Works

Warfarin decreases blood coagulation by inhibiting an enzyme that keeps the clotting factor, vitamin K, in circulation. It can interact with a number of drugs and foods and can be metabolized differently in different people, so people who take warfarin must be carefully monitored.

Taking Warfarin

Warfarin comes in tablets of varying doses. The dosage usually decreases with the age of the patient. It is taken with water any time.

Special Considerations

Warfarin interacts with a number of foods, supplements and medications. You’ll receive a list from your pharmacist or healthcare team. Read it carefully and let your doctor know whether you are taking any of those listed.

You will need to have your blood checked regularly to make sure you are getting the right dose of this medicine.

Always carry an identification card with your name, the brand name and dose of warfarin used and the name and phone number of your doctor or person to contact in an emergency.

Avoid activities that increase the risk of cuts and bruises and report any signs of bleeding to your doctor immediately.

Date Last Modified: January 21, 2011

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